Yarn tensioning means for knitting machines



Oct. 29, 1957 J. HELD 2,811,027

YARN TENSIONING MEANS FOR KNITTING MACHINES Filed Dec. 24, 1954 FLI:. E

i I I v I INVENTOR.

A TTORNE Y.

United States Patent YARN TENSIONING MEANS FOR KNITTING MACHINES Joseph Held, West Lawn, Pa., assignor to Textile Machine Works, Wyomissing, Pa., a corporation of Pennsylvania Application December 24, 1954, Serial No. 471,555

9 Claims. c1. 66-146) This invention relates to warp knitting machines such as tricot machines, and more particularly to means in such machines for maintaining a constant and uniform tension on the yarns during the knitting of the yarns into' fabric.

In textile fabricating machines such as tricot knitting the full length of the working portion of the machine, the

rod being carried on levers supported for movement about a fixed axis in the machine. The movements of the levers are controlled by springs or the like which resiliently maintain the rod in engagement with the yarns and permit the levers and rod to oscillate to follow the fluctuating demands for the yarns. However, in machines operating at high rates of speed, the weight mass of the levers and rod prevents the sensitive oscillating movements of the parts necessary to maintain the yarns under a uniform tension, thereby resulting in an uneven feeding of the yarns and the formation of fabric of inferior quality.

In another known form of tensioning means, the rod is supported on one or more thin flexible sheet metal plates extending in end-to-end relation along the entire length of the rod. The plates are carried on a support shaft which is adjustably mounted in hearings in the machineframe to permit the tension applied to the yarns to be varied. These thin sheet metal plates, while permitting rapid oscillations of the rod to follow the yarn demands, are difiicult and costly to manufacture. Also, in many instances, due to the rapid oscillations of the rod, the thin metal of the plates becomes fatigued which causes the plates to crack or break resulting in frequent machine stoppages to replace the damaged parts.

It is accordingly an object of the invention to provide means in a warp knitting machine for uniformly applying tension on the yarns which means is more economical to manufacture than present types and which will overcome the above mentioned operating and other difficulties.

Another object of the invention is to provide means for tensioning a plurality of yarns, particularly for use in a tricot knitting machine, which means is carried on spaced resilient members which are individually adjustable to exert a uniform tension on all of the yarns.

A further object of the invention is to provide a member for tensioning a plurality of yarns which member is carried on spaced coil springs which are individually adjustable to cause the member to exert a uniform tension on all of the yarns and which are simultaneously adjust- In one known Patented Oct. 29, 1957 ice able to vary the tensioning efiect of the member on the yarns.

Another object of the invention is the provision in a yarn tensioningdevice of the type referred to in the foregoing obje'cts'arid having a yarn guide rod over'which the yarns pass on their way to the knitting instrumentalities, of meansfor damping oscillations of the ends of the rod.

With these and other objects in view which will become. apparent from the following detailed description of the illustrative embodiment of the invention shown in the accompanying drawings, the invention resides in the novel elements, features of construction and cooperation of parts, as hereinafter more particularly pointed out in the claims. e

In the drawings:

Figure 1 is a cross-sectional view taken transversely through a portion of a tricot knitting machine a'ndinclud ing yarn tensioning and guiding mechanism according to the invention, do't-and-dash distance breaks being'sho'wn to indicate omission of intervening mechanism;

Fig. 2 is a plan view of the tensioning andguiding. mechanism on an enlarged scale taken from the left of. Fig. 1 and in the direction of the arrow A, distance breaks:

being shown'indicating omission of a portion of the overall length of the mechanism;

Fig. 3 is a cross-sectional view on an enlarged scale'.

taken along the line 3-3 of Fig. 2; a

Fig. 4 is a cross-sectional view on an enlarged scale taken alongthe line 4-4 of Fig.2; and

Fig. 5 is a cross-sectional view taken along theline of Fig. 2 and enlarged relative thereto.

In the drawing, Fig. 1 shows a portion of the yarn feeding and knitting means in a tricot knitting machine for forming the yarns into knitted fabric including needles 10, sinkers 11, a presser member 12 for periodicallyclosing the beards of the needles and front and rear groups of guide members 15 for yarns 16. The needles, sinkers, presser member and guide members are of a common form and are operated at high speed to form the yarns 16 into knitted fabric by mechanism such as shown in' my copending application Serial No. 378,852, filed September 8, 1953, or by mechanisms of known type.. .The yarns 16 are carried on supply beams 17 and are directed toward the knitting means beneath rods or shafts 20 mounted in frame members 21 forming a portion of the framework of the machine. From the guide rods 20, the yarns 16 from each beam 17 pass through a comb device 22,

carried in the frames 21, which is commonly provided in machines of this type to separate the individual yarns, and

from the comb device, the yarns extend around .a guide rod 25 to one group of guide members 15. As shown in Fig. l, the yarns from both beams 17 follow similar paths through their respective comb devices 22 and over the; corresponding guide rods 25 to one or the other of the groups of guide members 15.

.During certain parts of the movements of the needles 10 and guide members 15 and particularly as the guide.

members move back and forth through the needles to lap the yarns therearound, there is a fluctuating demand for the yarns which would normally cause a periodicinj crease and decrease of tension in the yarns between the guide members and guide rod 25. In order to maintain' the tension constant on the yarns as the needles andguides are movedthrough their respective paths, the guide rod must be mounted to follow the rapidly fluctuating de mands for the yarns. For this purpose, and in accordance with the instant invention, the guide rod 25, which, in this case is in the form of an elongated hollow tube, is carried in block members 26 spaced at intervals along the length of the rod. Each of the members 26 is adjustably 3. secured by a set screw 29 to an extending overhanging free end 27 of a coil spring (Figs. 2 and4). The coils of springs 30 surround and are supported by a shaft or rod 31 carried in and, held in adjusted position in. bearing portions of the frame members 21 by set screws 32; as shown in Fig, 2. Each spring 30 has its other end 35 bent at right anglesto the coils for engagement in an aperture 36' in a collar 37 carried'on the shaft SI. The collars 37 are individually rotatable on the shaft 31 to permit the springs 30 to be individually adjusted. The collars 37 are held in their adjusted positions on the shaft 31 by set screws 40 (Figs. 2 and 3). With this arrangement the yielding of the rod 25 under the pullv of the yarns is controlled by the inherent flexibility in both the coils and the overhanging ends 27of the springs. This not only permits the more rapid oscillating movements of the rod necessary to maintain aconstant tension on the yarns 16 when the machine is operating at high speed but also greatly, reduces the rate of deterioration or fatigue of the material normally resulting from its continuous flexing. Also the adjustability of the individual springs 30 permits a more uniform tension to be exerted by the guide rod 25 on all of the yarns 16 in the yarn sheet.

In many of the present high speed tricot knitting machines the guide rod 25 is oscillated in excess of two thousand times aminute during feeding and tensioning of the yarns. In some instances the rapid movements of the guide rod' 25 cause its free ends to vibrate in opposition to the normal movements of the rod which adversely affects the formation of the, loops along the edges of the fabric. In accordance with the invention and in order to stabilize or dampen the movement at the ends of the guide rod 25, a'flexible. member 41, of rubber or the like, is' inserted in the bore at each end of the hollow rod (Figs. 2 and 5) to form extensions of the rod. The members or extensions 41 have their outer end supported by the free ends ofarms 42 which are secured by screws '45 to the shaft 31 adjacent the opposite ends of the guide rod 25.

Of course, the improvements specifically shown and de scribed by which the above results are obtained, can be changed and modified in various ways without departing from the invention, herein disclosed and hereinafter claimed.

I claim:

1. A yarn guiding and tensioning device for warp knitting machines including a support member and a guide rod in combination with resilient supporting means for said guide rod including a coil spring surrounding said support member, means for connecting one end of said coil spring to said guide rod and means for connecting the other end of said coil spring to said support member.

2. A yarn guiding and tensioning means for a tricot knitting machine including a support member for mounting on said machine, a guide bar, resilient. means coiled about said support member and having one end adjustably connected to said support member and they other end attached to said guide bar, said resilient'means permitting oscillating movements of said guide bar by the yarn, and means engaging the ends of said guide bar to dampen movements of the ends thereof. I

' 3. In. a warp knitting machine having means for guiding and tensioning a plurality of warp yarns including a support member carried in adjustably fixed relation on the machine, a yarn guide rod, a coil spring mounted in surrounding relation on said member and having one end connected to said guide rod, and a collar adjustably carried on said member for anchoring the other end of said. coil spring.

4. In a, warp knitting machine having means for supply- 5. In a warp knittingmachine having means for supply ing asheetof yarns, means for forming said yarns into fabric, and-means fonapplyingtension. to said yarns, said last named means including a support member mounted on the machine and an elongated guiderod over which the yarns are adapted to pass to said fabric forming means, the improvement comprising coil springs surrounding said support member atspaced intervals, and. having extending ends supporting said, guide rod, and means for adjustably anchoring the other ends of said. springs: to said, support member. 1

6. In a warp knitting machine having means for supplying a, sheet of yarns, means for forming said yarns into fabric, and means for applying tension to said yarns, said last namedmeans including asupport member mounted on the machine and an elongated guide rod over which the yarns are. adapted, to passto said fabric forming means, the improvement, comprising. coil springs surrounding said support member at spaced intervals and having extending ends supporting. said guide. rod, means for adjustably anchoring the other ends of said springs to said support member and meansadjacent the ends of the guide rod. for damping oscillations of said ends.

7.. In. a. warp: knitting machine having means for supplyin}; a sheet of. yarns, means for forming, said yarns into fabric, and means for applying. tensionto said yarns, said last named means. including a support member mounted on the. machine. and. an elongated guide rod over which the yarns are adapted to pass tosaid fabric forming means, the improvement comprising coil springs surrounding said support member at spaced intervals and having extending ends supporting said guide rod, means for adjustably anchoring the other ends of said springs to said support member and means adjacent the ends of the guide rod for damping oscillations of said ends, said last named means comprising resilient extensions on said guide rod and members connecting said extensions to said sup-- port member.

8. A tension device for a warp knitting machine comprising a yarn guide rod, a coil spring, means supporting said coil spring in substantial parallelism with said yarn guide rod, meansfor anchoring one end of said coil spring and means for attaching the other end of said coil spring to said yarn guide rod for support thereof.

9. A tension device for a warp knitting machine comprising a yarn guide rod,a coil spring, means supporting said coil spring in substantial parallelism with said yarn guide rod, means for adjustably anchoring one, end of said coil spring and means for attaching the other end of said coil spring to said yarn guide rod for support thereof.

References Cited in the me of this patent UNITED STATES PATENTS 1,154,251. Keeton Sept. 21, 1915 2,637,184 Schoenster May 5, 1953 2,674,110 Roughsedge et al. Apr. 6, 1954 2,699,051 Noe Jan. 11, 1955. 

